I've been using Comply foam tips on in-ears for years. Most recently got some for my Air Pods Pro. They give a good seal, and they help keep the earbuds from slipping out. The downsides are that they aren't quite as easy to pop in (since you need to squish the foam and then let it expand inside), they can be irritating over long periods of time, and you will need to replace them every few months.

Despite those issues, I still find the foam tips far better than any silicone tip I've tried. Those never feel like they fit right, either being too small or feeling like they're so big that they're trying to pop themselves back out.